Fluid pressure actuated clamp



Feb. 19, 1963 c. s. EINSIEDLER FLUID PRESSURE ACTUATED CLAMP 2 Sheets-Sheet 1 Filed. June 6. 1960 N wt ATTORNEY Feb. 19, 1963 c. s. EINSIEDLER 3,078,088

FLUID PRESSURE ACTUATED CLAMP Filed June 6. 1960 2 Sheets-Sheet 2 INVEN TOR. CHARLES STEPHEN E/NS/EDLER ATTORNEY United States Patent 3,078,038 FLUED PRESSURE ACTUATED CLAMP Charles Stephen Einsiedler, 67 King Philip Circle, Warwick, RI. Filed June 6, 1960, Ser. No. 34,070 3 (llaims. (Cl. 269-20) This invention relates to a fluid pressure actuated clamp and more particularly to a pivotally and slidingly mounted lever provided with a hydraulically operated cylinder on one end and a work clamping surface on the opposite end.

One of the objects of the present invention is to provide a fluid pressure actuated clamp which will instantaneously apply and instantaneously release great holding pressure on a work piece operatively positioned in a machine tool.

Another object of the present invention is to provide a fluid pressure actuated clamp which is extremely small in size in proportion toits holding power.

Still another object of the present invention is to provide a fluid pressure actuated clamp which is inexpensive to manufacture and is simple in construction and operation.

And still another object of the present invention is to provide a fluid pressure actuated clamp which is easily placed into and out of work clamping position and which is self adjusting to varying thicknesses of the work pieces.

' And still another object of the present invention is to provide a fluid actuated clamp in which the holding force applied to the work piece is uniformly controlled and adapted for repetitive operations.

A further object of the present invention is to provide a fluid actuated clamp having a suflicient force to hold a work piece against the torque of a cutting tool.

And still a further object of the present invention is to relieve a machine operator of the fatigue induced by manual work clamping devices.

' Another object of the present invention is to provide a fluid actuated clamp with the work engaging surface and the surface of the fluid actuated clamp in a common plane.

Still a further object of the present invention is to provide a fluid actuated clamp which is manually positioned over the work piece with physical ease and which is readily checked for accuracy of position, visually.

A further object of the present invention is to provide a fluid actuated clamp which permits the visual observation of the position of the clamping means in relation to the work to be clamped and the visual observation of the functioning of the hydraulic cylinder.

Other objects of the present invention will become apparent in part and be pointed out in part in the following specification and claims.

Referring to the drawings in which similar characters of reference indicate corresponding parts in all the figures:

FIGURE 1 is a plan view of the new and improved fluid pressure actuated clamp.

FIGURE 2 is a side elevational view of FIGURE 1.

FIGURE 3 is a right hand front elevational view of FIGURE 2.

FIGURE 4 is a transverse cross sectional view taken aiong line 4-4 of FIGURE 1.

In proceeding with this invention there is provided a clamping lever, generally indicated by reference character 11, having a top plate 12 provided with a slot 17 which may be elongated. Two oppositely disposed and parallel sides 13, 14 are integrally connected to top plate 12. A step 15, having a work engaging surface 18, is formed in the rear section of top plate 12. An elevated and horizontally projecting member 16 provided with an orifice 19 which may be elongated, is formed in the front section of top plate 12. A vertical wall 24 forms the rear section of a horizontally projecting U-shaped cavity 25 with sides 13, 14 integrally connected to vertical wall 24 3,078,088 Patented Feb. 19, 1963 to form the sides of the U. Horizontally projecting member 16 forms a cover for said cavity 25 and projects beyond said cavity 25. A horizontal ridge 20 is formed in vertical wall 24 and in sides 13, 14-. Sides 13, 14 are recessed or relieved at 30, 31 respectively, to permit visual observation of the operation of the hydraulic cylinder, as will presently appear. A chamber 21 is formed between the underside 22 of top plate 12, the front edge 23' of step 15 and the back surface 24 of horizontally projecting member 16. Chamber 21 is open on the bottom side.

A bolt 40 which passes through elongated slot 17 is secured to the table 41 of a machine tool shown in dotdash lines FIGURES l, 2 and 3. A T shaped nut 42 secured to the end of bolt 40 is located in a T slot 43 in table 41. A look nut 44 rotatively mounted upon bolt 40 abuts T shaped nut 42. A washer 45 is freely mounted upon bolt 40 and rests upon lock nut 44. A washer 46, loosely mounted upon bolt 40 abuts the bottom surface of sides 13, 14. A second washer 47 is loosely mounted upon bolt 40. A coil spring 48 is interposed between washers 47 and 45 to yieldingly urge clamping lever 11 upward away from table 41. (See FIGURE 2). A washer 49A slidingly mounted upon bolt 40 rests upon the top surface of top plate 12. A nut 50 is rotatively mounted upon bolt 40 to provide a stop against which spring 48 may yieldingly urge clamping lever 11.

A hydraulic cylinder is provided and generally indicated by reference character 50A. Hydraulic cylinder 50A consists of a piston chamber having a cylindrical side wall 52, a base 53 and an outwardly extending lip 49. Internally, the piston chamber is provided with a piston engaging sur face 54 and a fluid engaging work area 55.

A piston 56 is provided with an axial passageway 57 having a threaded area 57A in one end. Externally, piston 56 is provided with a sliding surface 56A having a circular groove 58 in one end and a neck portion 59 provided with a thread 59A which terminates the other end. A tapered shoulder 60 is formed between sliding surface 56A and neck portion 59.

A packing 61 is provided in circular groove '58 so that fluid at extremely high pressure cannot pass between sliding surface 56A and piston engaging surface 54. The packing creates a fluid tight seal.

Piston 56 is slidably mounted in the piston chamber with sliding surface 56A slidingly engaging piston engaging surface 54. Neck portion 5 9 is located in elongated slot 19 and secured in position by means of tapered shoulder 60 engaging the bottom edge of said elongated slot 19 and a nut 53 which rotatively engages threads 59A. Nut 63 abuts the top surface of horizontally projecting member 16, thereby securing hydraulic cylinder SilA to horizontally projecting member 16. A coil spring 65 is interposed between outwardly extending lip 49 and horizontal ridge 20. A pipe fitting 67 is secured to threaded area 57A and provides an axial extension to axial passageway 57.

A work piece 70, illustrated in dot and dash lines in FIGURE 2 is placed upon table 41. A set of mechanics blocks 71, '72 is also placed upon table 41. Blocks 71, '72 are adjusted to a height substantially equal to the height of work piece 70.

Clamping lever 11 is placed so that work engaging surface 15' overlies work piece 70 and base 53 overlies blocks 71, 72. Air or fluid under pressure from a source (not shown) enters axial passageway 57 through pipe fitting 67 to engage fluid engaging work area 55, whereby, base 53 of the piston chamber moves downward, in the direction of the arrow FIGURES 2 and 4, to engage blocks 71, 72. The relative movement between piston 56 and the piston chamber will cause horizontally projecting member 16 to move upwardly in a direction opposite to the direction of the arrows in FIGURES 2 and 4, thereby causing clamping lever 11 to pivot on bolt 40 so that work engaging surface 18 will engage work piece 76 with a force generated by the fluid pressure acting on fluid engaging work area 55. Spring 65 is compressed during the relative movement between piston 56 and the piston chamber.

Upon release of the fluid pressure in axial passageway 57, spring 65 will cause the piston chamber to move in a direction opposite to the direction of the arrows in FIGURES 2 and 4- to restore the position of piston 56 in the piston chamber to that shown in FIGURES 2 and 4, the initial starting position. It will be noted that recess 31 in FIGURE 2 allows the machine operator to observe whether or not the bottom 53 of the piston chamber is moving downward in the direction of the arrow and in what direction of alignment in relation to blocks 71, 72 the bottom is moving. lso the open area of the horizontally projecting U-shaped cavity 25 permits a clear view of the action of spring 65, and the alignment of the piston chamber with blocks 71, 72.

Having shown and described a preferred embodiment of the present invention, by way of example, it should be realized that structural changes could be made and other examples given without departing from either the spirit or scope of this invention.

What I claim is:

l. A fluid pressure actuated clamp comprising a clamping lever consisting of a top plate provided with an elongated slot, two oppositely disposed parallel sides integrally connected to said top plate, a step having a work engaging surface formed in the rear section of said top plate, an elevated horizontally projecting member provided with an elongated orifice formed in the front section of said top plate, a vertical wall depending from said horizontally projecting member, said two oppositely disposed parallel sides in co-operation with said vertical wall forming a horizontal U-shaped cavity, a horizontal ridge formed in said vertical wall and in said two oppositely disposed parallel sides, a bolt located in said elongated slot, means to yieldingly pivot said clamping lever to said bolt, a hydraulic cylinder consisting of a piston, a piston chamber, said piston slidingly mounted in said piston chamber, said piston secured to said elevated horizontally projecting member and located in said elongated orifice, said piston chamber located in said horizontal U-shaped cavity, resilient means interposed between said piston chamber and said horizontal ridge, and iluid pressure means actuating said piston chamber to provide relative movement between said piston and piston chamber and against the force of said resilient means to actuate the means to yieldingly pivot said clamping lever to said bolt whereby said work engaging surface moves in a work producing stroke.

2. A fluid pressure actuated clamp comprising a clamping lever consisting of a top plate provided with an elongated slot, two oppositely disposed parallel sides integrally connected to said top plate, a step having a work engaging surface formed in the rear section of said top plate, an elevated horizontally projecting member, provided with an orifice, formed in the front section of said top plate, a vertical wall depending from said horizontally projecting member, said two oppositely disposed parallel sides in co-operation with said vertical wall form ing a horizontal U-shaped cavity, a horizontal ridge formed in said vertical wall and in said two oppositely disposed parallel sides, a bolt located in said elongated slot, means to yieldingly pivot said clamping lever to said bolt, a hydraulic cylinder consisting of a piston chamber having a cylindrical side wall, a base and an outwardly extending lip, a piston engaging surface formed internally of said cylindrical side wall, a fluid engaging work area formed internally of said base, said piston chamber located in said horizontal U-shaped cavity, a coil spring interposed between said horizontal ridge and said outwardly extending lip, a piston provided with a sliding surface, a neck portion and an axial passageway, said sliding surface slidingly engaging said piston engaging surface. said neck portion located in said orifice. means to secure said neck to said horizontally projecting mem ber whereby fluid pressure passing through said axial passageway and acting on said fluid engaging work area causes relative movement between said piston and said piston chamber against the tension of said coil spring, to actuate the means to yieldingly pivot said clamping lever to said bolt whereby said work engaging surface moves in a work producing stroke 3. A fluid pressure actuated clamp comprising a clamping lever consisting of a top plate provided with a slot, :1 step having a work engaging surface formed in the rear section of said top plate, an elevated horizontally projecting member, provided with an orifice, formed in the front section of said top plate, a vertical wall depending from said horizontally projecting member, a horizontal ridge formed in said vertical wall, a bolt located in said slot, means to yieldingly pivot said clamping lever to said bolt, a hydraulic cylinder consisting of a piston chamber having a cylindrical side wall, a base and an outwardly extending lip, a piston engaging surface formed internally of said cylindrical side wall, a fiuid engaging work area formed internally of said base, said piston chamber located adjacent said horizontal ridge, a coil spring interposed between said horizontal ridge and said outwardly extending lip, a piston provided with a sliding surface, a neck portion and an axial passageway, said sliding surface slidingly engaging said piston engaging surface, said neck portion located in said orifice, means to secure said neck to said horizontally projecting member, whereby fluid pressure passing through said axial passageway and acting on said fluid engaging work area causes relative movement between said piston and said piston chamber against the tension of said coil spring, to actuate the means to yieldingly pivot said clamping lever to said bolt whereby said work engaging surface moves in a work producing stroke.

References Cited in the file of this patent UNITED STATES PATENTS 1,536,310 Rothlisberger May 5, 1925 2,650,523 Zwick Sept. 1, 1953 FOREIGN PATENTS 6,158 Great Britain of 1906 63,794 enmark July 23, 1945 

3. A FLUID PRESSURE ACTUATED CLAMP COMPRISING A CLAMPING LEVER CONSISTING OF A TOP PLATE PROVIDED WITH A SLOT, A STEP HAVING A WORK ENGAGING SURFACE FORMED IN THE REAR SECTION OF SAID TOP PLATE, AN ELEVATED HORIZONTALLY PROJECTING MEMBER, PROVIDED WITH AN ORIFICE, FORMED IN THE FRONT SECTION OF SAID TOP PLATE, A VERTICAL WALL DEPENDING FROM SAID HORIZONTALLY PROJECTING MEMBER, A HORIZONTAL RIDGE FORMED IN SAID VERTICAL WALL, A BOLT LOCATED IN SAID SLOT, MEANS TO YIELDINGLY PIVOT SAID CLAMPING LEVER TO SAID BOLT, A HYDRAULIC CYLINDER CONSISTING OF A PISTON CHAMBER HAVING A CYLINDRICAL SIDE WALL, A BASE AND AN OUTWARDLY EXTENDING LIP, A PISTON ENGAGING SURFACE FORMED INTERNALLY OF SAID CYLINDRICAL SIDE WALL, A FLUID ENGAGING WORK AREA FORMED INTERNALLY OF SAID BASE, SAID PISTON CHAMBER LOCATED ADJACENT SAID HORIZONTAL RIDGE, A COIL SPRING INTERPOSED BETWEEN SAID HORIZONTAL RIDGE AND SAID OUTWARDLY EXTENDING LIP, A PISTON PROVIDED WITH A SLIDING SURFACE, A NECK PORTION AND AN AXIAL PASSAGEWAY, SAID SLIDING SURFACE SLIDINGLY ENGAGING SAID PISTON ENGAGING SURFACE, SAID NECK PORTION LOCATED IN SAID ORIFICE, MEANS TO SECURE SAID NECK TO SAID HORIZONTALLY PROJECTING MEMBER, WHEREBY FLUID PRESSURE PASSING THROUGH SAID AXIAL PASSAGEWAY AND ACTING ON SAID FLUID ENGAGING WORK AREA CAUSES RELATIVE MOVEMENT BETWEEN SAID PISTON AND SAID PISTON CHAMBER AGAINST THE TENSION OF SAID COIL SPRING, TO ACTUATE THE MEANS TO YIELDINGLY PIVOT SAID CLAMPING LEVER TO SAID BOLT WHEREBY SAID WORK ENGAGING SURFACE MOVES IN A WORK PRODUCING STROKE. 